Method and apparatus for efficiently using a battery in a smartphone having a navigation system

ABSTRACT

This invention relates to a method and apparatus to optimize energy consumption in a mobile phone having a navigation system. More specifically, this invention relates to a navigation-based method and apparatus to efficiently use a smartphone battery to deliver the highest possible location accuracy to the driver. In one embodiment, when the driver is travelling from a complex route segment to a less complex route segment, a current location sensor is switched to another location sensor with lower location accuracy which consumes less battery power. In another embodiment, when the driver is travelling from a less complex route segment to a complex route segment, the navigation system continues to use a location sensor with lower accuracy until the navigation system determines that switching to higher accuracy location sensor is necessary to conserve more battery power. The navigation system can determine a best timing to switch according to the driver&#39;s familiarity with the route segment or geographical area.

FIELD OF THE INVENTION

This invention relates to a method and apparatus to optimize energyconsumption in a mobile phone having a navigation system. Morespecifically, this invention relates to a navigation-based method andapparatus to efficiently use a mobile phone battery to deliver thehighest possible location accuracy to the driver.

BACKGROUND OF THE INVENTION

During the advance of computer technology, navigation devices have beenwidely used for over a decade. The navigation device can, not onlydetermine the driver's current position by utilizing the GlobalPositioning System (GPS), but also provide different routing informationbetween the vehicle's current position and the destination. In order toperform abovementioned functions, the navigation device is usuallyequipped with a sophisticated navigation system comprising navigationcomputer programs and one or more detailed database to store and providemaps, road networks, geographical features, and waypoint orpoint-of-interest (POI) information.

Recently, connected portable devices (portable navigation devices(PNDs), smartphones, etc.) have become more popular and affordable. Mostconnected portable devices are equipped with location sensors, such asglobal positioning system (GPS), cellular or Wi-Fi triangulation, thatprovide turn-by-turn navigation guidance to the user. A common problemwith these devices is their rapid consumption of the electrical powerstored in the battery when the location sensors are operated, whichoften results in a disrupted user experience when the devices are offdue to insufficient battery power.

Regarding the location accuracy of the abovementioned location sensors,GPS receiver has the highest location accuracy, followed by Wi-Fi andGSM. In terms of power consumption, the same order would be applied toshow the power consumption, from the highest to the lowest. As can beseen in FIG. 1 (from Professor Romit Roy Choudhury, Duke University,which is incorporated herein by reference), if the battery life is eighthour when using GPS receiver, it can be extended to about sixteen hourswhen using Wi-Fi, and about forty hours when using GSM.

U.S. Pat. No. 7,577,516 to Dobeck et al. discloses a portable dataterminal generally comprising a battery, a central controller, a GPSsystem, and an auxiliary processor, wherein the central controller thathas a sleep state wherein at least some of the functionality of thecentral controller is limited to conserve battery power, as shown inFIG. 2. However, Dobeck does not disclose anything related to switchingthe GPS receiver to other less accurate location sensors such as Wi-Fior GSM, according to the driver's familiarity of the route or location,or the complexity of the route or location.

Japanese Laid-Open Patent Application No. 2007187620 discloses a methodand system to reduce power consumption in a cellular phone with GPSfunction. More specifically, the GPS will be turned off, and stores aGPS assist signal when arriving at a first reference point. Whenarriving at a second reference point, the GPS will be again turned onand the stored GPS assist signal will be used for detecting thevehicle's current position. However, like Dobeck, it does not discloseanything related to switching the GPS receiver to other less accuratelocation sensors such as Wi-Fi or GSM, according to the driver'sfamiliarity of the route or location, or the complexity of the route orlocation.

Therefore, there remains a need for a new and improved apparatus andmethod for efficiently using a battery in a mobile phone to deliver thehighest possible location accuracy to the driver, according to thedriver's familiarity of the route or location, or the complexity of theroute or location.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method andapparatus for optimizing battery usage in a mobile phone to deliver thehighest possible location accuracy to the driver, by using locationmatching technologies and realizing the geographic nature of thelocation the driver is at and/or will be going to.

It is another object of the present invention to provide a method andapparatus for optimizing battery usage in a mobile phone by triggering alocation sensor with lower accuracy, according to the driver'spredetermined time intervals, such as the driver's calendar which storeshis/her activities.

It is a further object of the present invention to provide a method andapparatus for optimizing battery usage in a mobile phone by using thedriver's calendar and driving history to determine the driver'sfamiliarity of certain locations, and the lower accuracy location sensormay be triggered if the system determines the driver is familiar with alocation.

It is still a further object of the present invention to provide amethod and apparatus for optimizing battery usage in a mobile phone thatwhen the system determines the driver may be unfamiliar with thelocation or route, the system may use the location sensor with the loweraccuracy, namely consuming less power, as long as possible, then switchto the location sensor with higher accuracy to conserve more batterypower.

This invention relates to a method and apparatus to optimize energyconsumption in a mobile phone while operating a navigation system. Morespecifically, this invention relates to a navigation-based method andapparatus to efficiently use a mobile phone battery to deliver thehighest possible location accuracy to the driver. In one aspect, themobile phone may include a memory device; a transceiver; a battery, acontrol unit; and a navigation system having more than one locationsensor with different accuracies, wherein the control unit is adapted toswitch one location sensor to another when a predetermined conditionoccurs to more efficiently use the battery in the mobile phone.

In one embodiment, the location sensor may include a GPS receiver,Wi-Fi, or GSM sensor. As noted above, the GPS receiver has the highestlocation accuracy, followed by Wi-Fi and GSM. Meanwhile, the GPSreceiver may consume more battery power than Wi-Fi or GSM. In anexemplary embodiment, the control unit may switch one location sensor toanother with lower location accuracy to save the battery power when thecontrol unit determines that the geographic nature of the destination orthe route the driver will be taking is not complex.

On the other hand, in another embodiment, when the control unitdetermines that the geographic nature of the destination or the routethe driver will be taking is complex, the control unit is configured touser the location sensor with lower accuracy to the highest extentbefore switching to the high accuracy one.

According to another aspect in the present invention, a method for moreefficiently using a battery in the mobile phone while operating anavigation system may include the steps of generating a route accordingto an address or a location enter by a driver; dividing the route intomore than one route segments; determining route complexity in each routesegment; and automatically switching one location sensor in thenavigation system to another location sensor therein to maximize theusage of the smartphone battery.

In one embodiment, when the driver is travelling from a complex routesegment to a less complex route segment, the location sensor is switchedto another location sensor with lower location accuracy which consumesless battery power. In another embodiment, when the driver is travellingfrom a less complex route segment to a complex route segment, thenavigation system continues to use a location sensor with lower accuracyuntil the navigation system determines that switching to higher accuracylocation sensor is necessary to conserve more battery power.

In a further embodiment, the step of automatically switching onelocation sensor to another location sensor when the route complexitychanges includes the step of determining a best timing to switch thelocation sensor with lower location accuracy to another location sensorwith higher location accuracy. In still a further embodiment, the stepof determining a best timing to switch the location sensor with lowerlocation accuracy to another location sensor with higher locationaccuracy includes the step of receiving information including priorcompletion time to the destination and any anticipatory delay;historical and predictive traffic conditions; distance between thecurrent position and destination; and population density of the currentvehicle position, destination and all areas in between.

In an exemplary embodiment, the method for more efficiently using abattery in a smartphone while operating a navigation system may furtherinclude the step of determining the driver's familiarity of the route orthe geographical nature of the address or location. In a differentembodiment, the step determining the driver's familiarity of the routeor the geographical nature may include the step of checking the driver'shistorical activities stored in the memory device.

According to another aspect of the present invention, a smartphonedevice may include a database, a memory device, a wireless protocol, atransceiver, an antenna and a plurality of phone applications. To enablethe user to place and receive phone calls in a conventional manner, thesmartphone may also include a user interface, a control unit, a keypad,a display, a microphone, a speaker and a battery. For example, the usermay place a call by entering a phone number using the keypad. The userinterface is adapted to communicate the user's action to the controlunit, along with displaying information to the user via the display. Thecontrol unit is configured to place the call using the transceiver andthe antenna. The user may engage in the phone conversation in aconventional way using the microphone and the speaker. The wirelessprotocol conforms to the wireless communication standard and providesthe smartphone data communication capabilities. The phone applicationmay include a navigation system having more than one location sensorwith different accuracies, and the control unit is adapted to switch onelocation sensor to another when a predetermined condition occurs to moreefficiently use the battery in the smartphone device.

In one embodiment, the navigation system may equip with aposition/distance measuring device which may include a GPS receiver, aWi-Fi positioning system (WPS) and a GSM sensor, wherein the GPSreceiver has the highest location accuracy, followed by the WPS and GSMsensor. On the other hand, the GPS receiver may consume more batterypower than the WPS and GSM.

In another embodiment, the navigation system may include a routegenerating unit to retrieve map and road network data from a databaseand generate a calculated route. The route generating unit may include aroute dividing unit to divide the calculated route into more than oneroute segment and a route complexity determining unit. As mentionedabove, a current location sensor may be switched to another one in thenavigation (either with higher or lower location accuracy) when theroute complexity changes. In another embodiment, the route complexitydetermining unit may be operatively communicate with the route dividingunit to properly assign route complexity to each route segment. In adifferent embodiment, the complexity can be encoded into the mapdatabase in the navigation system.

In a further embodiment, the route complexity determining unit canretrieve the driver's historical activities from the memory device todetermine the driver's familiarity with respect to the route segments.

The present invention together with the above and other advantages maybest be understood from the following detailed description of theembodiments of the invention illustrated in the drawings below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the residual battery life versus the operating timeamong three different location sensors in a smartphone.

FIG. 2 illustrates a prior art, related to a portable data terminalgenerally comprising a battery, a central controller, a GPS system, andan auxiliary processor, wherein the central controller that has a sleepstate wherein at least some of the functionality of the centralcontroller is limited to conserve battery power.

FIG. 3 illustrates a functional block diagram showing an example ofstructure of a smartphone implementing the method and apparatus forefficiently using a battery in a smartphone while operating a navigationsystem.

FIGS. 4, 4 a and 4 b depict an example to illustrate the complexity ofroute segments and geographical nature of an area.

FIG. 5 illustrates a functional block diagram showing an example ofstructure of a navigation system implementing the method and apparatusfor efficiently using a battery in a smartphone.

FIGS. 5 a and 5 b illustrate two embodiments of FIG. 5.

FIG. 6 illustrates another aspect of the present invention, depicting amethod for efficiently using a battery in a smartphone while operating anavigation system.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below is intended as a description ofthe presently exemplary device provided in accordance with aspects ofthe present invention and is not intended to represent the only forms inwhich the present invention may be prepared or utilized. It is to beunderstood, rather, that the same or equivalent functions and componentsmay be accomplished by different embodiments that are also intended tobe encompassed within the spirit and scope of the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention belongs. Although any methods, devicesand materials similar or equivalent to those described can be used inthe practice or testing of the invention, the exemplary methods, devicesand materials are now described.

All publications mentioned are incorporated by reference for the purposeof describing and disclosing, for example, the designs and methodologiesthat are described in the publications which might be used in connectionwith the presently described invention. The publications listed ordiscussed above, below and throughout the text are provided solely fortheir disclosure prior to the filing date of the present application.Nothing herein is to be construed as an admission that the inventors arenot entitled to antedate such disclosure by virtue of prior invention.

This invention relates to a method and apparatus to optimize energyconsumption in a mobile phone while operating a navigation systemtherein. More specifically, this invention relates to a navigation-basedmethod and apparatus to efficiently use a mobile phone battery todeliver the highest possible location accuracy to the driver. As statedabove, a common problem with these mobile phone devices is their rapidconsumption of the electrical power stored in the battery when thelocation sensors are operated. Since the location sensor with higheraccuracy consumes more energy, this invention is adapted to switch thehigh accuracy sensor (e.g. GPS receiver) to some lower accuracy sensors(e.g. Wi-Fi, GSM) to save battery power, under certain circumstances.

Referring to FIG. 3, a smartphone device 300 may include a database 310,a memory device 320, a wireless protocol 330, a transceiver 340, anantenna 350, and a plurality of phone applications 360. To enable theuser to place and receive phone calls in a conventional manner, thesmartphone 300 may also include a user interface 370, a control unit380, a keypad 390, a display 391, a microphone 392, a speaker 393 and abattery 394. For example, the user may place a call by entering a phonenumber using the keypad 390. The user interface 370 is adapted tocommunicate the user's action to the control unit 380, along withdisplaying information to the user via the display 391. The control unit380 is configured to place the call using the transceiver 340 and theantenna 350. The user may engage in the phone conversation in aconventional way using the microphone 392 and the speaker 393. Thewireless protocol 330 conforms to the wireless communication standardand provides the smartphone 300 data communication capabilities. Thephone application 360 may include a navigation system 500 having morethan one location sensor with different accuracies, and the control unit380 is adapted to switch one location sensor to another when apredetermined condition occurs to more efficiently use the battery inthe smartphone device 300.

In one embodiment shown in FIG. 5 a, the navigation system 500 may equipwith a position/distance measuring device 502 which may include a GPSreceiver 551, a Wi-Fi positioning system (WPS) 552 and a GSM sensor 553,wherein the GPS receiver 551 has the highest location accuracy, followedby the WPS 552 and GSM sensor 553. On the other hand, the GPS receiver551 may consume more battery power than the WPS 552 and GSM 553.

The navigation system 500 may include a route generating unit 521 toretrieve map and road network data from a database 310 and generate acalculated route. The route generating unit 521 may include a routedividing unit 555 to divide the calculated route into more than oneroute segment and a route complexity determining unit 556. As mentionedabove, a current location sensor may be switched to another one in thenavigation 500 (either with higher or lower location accuracy) when theroute complexity changes. In another embodiment, the route complexitydetermining unit 556 may be operatively communicate with the routedividing unit 555 to properly assign route complexity to each routesegment. In a different embodiment, the complexity can be encoded intothe map database in the navigation system 500.

In a further embodiment, the route complexity determining unit 556 canretrieve the driver's historical activities from the memory device 320to determine the driver's familiarity with respect to the routesegments. For example, when the route complexity determining unit 556may consider the driver familiar in a route segment if he/she drives onthat route segment several times a week. On the other hand, if thedriver only drives on that route segment several times a year, anopposite result may be generated. The determining unit 556 may alsoconsider the age of the historical activities. For example, thedetermining unit 556 may consider the driver is unfamiliar with theroute segment even if the driver used to drive on the same route segmentfor three years, but haven done so for five years.

In still a further embodiment shown in FIG. 4, the route 400 is dividedin more than one route segments (410 to 450) according to the cities thedriver may drive by. Here, the route complexity may be defined based onthe population, traffic, road networks . . . etc. in the city. Forexample, the route complexity may be higher in segments 410 and 440(Cities B and J) due to dense street grinds, while the route complexitymay be lower in segments 420, 430 and 450 (Cities C, D and K). When thedriver is driving from a complex route segment such as 410 to a lesscomplex route segment 420, the current location sensor is switched toanother location sensor with lower location accuracy which consumes lessbattery power. If the driver is traveling to a route segment withsimilar route complexity, the location sensor may not be switched.Similarly, if the driver is travelling from a geographic area 460 (shownFIG. 4 a) to a less complex geographic area 470 (shown in FIG. 4 b), thecurrent location sensor can be switched to another location sensor withlower location accuracy which consumes less battery power.

On the other hand, if the driver is driving from a less complex routesegment 420 (City C) to a more complex route segment 430 (City D), or aless complex geographic area 470 to a more complex geographic are 460,the current location sensor can be switched to another location sensorwith higher location accuracy, at a best timing to conserve as muchbattery power as possible. It is known that the location sensor withhigher location accuracy consumes more battery power than that withlower location accuracy. In order to conserve more battery power, thelocation sensor switching process may not start as soon as the routecomplexity changes from low to high. More particularly, the navigationsystem 500 may continue to use the location sensor with lower accuracyuntil the system 500 determines that switching to higher accuracylocation sensor is necessary.

Furthermore, the most accurate location sensor such as the GPS receiver551 may be necessary for initial route calculation before the system 500can determine when to switch to higher accuracy location sensor. Thesystem 500 may consider the following factors to determine the besttiming to switch from low accuracy to higher accuracy location sensor toconserve more battery power: (1) prior completion time to thedestination and any anticipatory delay; (2) historical and predictivetraffic conditions; (3) distance between the current position anddestination; and (4) population density of the current vehicle position,destination and all areas in between.

In an exemplary embodiment, the control unit 380 may be adapted tocalculate a best timing to switch the location sensor from low accuracyto higher accuracy by considering the abovementioned factors. Forexample, if there is an activity in the driver's calendar at 2 pm, anestimated time of arrival (ETA) to the activity is thirty minutes, andtime for the system 500 is about ten minutes, the best timing to switchto the more accurate location sensor may take place at 1:20 pm to givethe system 500 sufficient time to analyze and predict the routeconditions from the user's location to the next activity and deliver thebest route to the user. The system 500 may continue to use the highprecision sensor until the user reaches a familiar location or route,upon which the system 500 can determine whether to switch to a lesserpower consuming/less accuracy sensor or keep using the more precise highpower consumption sensor, according to the user's familiarity of thelocation or route. In other words, the user's familiarity of thelocation or route is highly related to the complexity of the route orlocation which may be determined by the system 500.

In a different embodiment, the control unit 380 may be configured tomeasure the power level of the battery 394 and communicate suchinformation to the navigation system 500, such that the navigationsystem 500 can efficiently use the battery power while providing thehighest possible location accuracy to the driver. For example, when thesystem 500 realizes that the battery level is only sufficient for fiveminutes using the high accuracy location sensor, e.g. GPS receiver 551,and estimated time of arrival to the destination is twenty minutes, thesystem 500 may immediately switch to the low accuracy location sensorand route the driver to the less complex route segments by consideringthe abovementioned four factors. In another embodiment, the navigationsystem 500 may route the driver to the familiar route segments beforethe power goes off.

FIG. 5 is a block diagram showing an example of detail structure of thenavigation system 500 for implementing the present invention. Thenavigation system 500 includes a user interface 370 and a position anddistance measuring device 502 for measuring the present vehicle positionor user position. For example, the position and distance measuringdevice 502 has a speed sensor for detecting a moving distance, agyroscope for detecting a moving direction, a microprocessor forcalculating a position, a GPS (global positioning system) sensordetecting the vehicle's current position by receiving radio wavesgenerated by a satellite. In one embodiment, the GPS receiver 551 is,for example, used as the current position detection portion, but thespeed sensor, a steering sensor, an altimeter or the like can be usedindividually or in combination instead of the GPS receiver 551. In otherembodiments, the position and distance measuring device 502 may alsoinclude the Wi-Fi positioning system (WPS) 552 and a GSM sensor 553, asshown in FIG. 5 a.

As shown in FIG. 5, the navigation system 500 may also include aguidance providing unit 503 to provide guidance information to thedriver on a lane basis; a map information memory 507 for storing the mapinformation; a route generating unit 521 adapted to retrieve the map androad network data from the database and generate a calculated route; anda database memory 508 for storing database information such a point ofinterest (POI) information. In one embodiment shown in FIG. 5 b, theroute generating unit 521 may include a route dividing unit 555 todivide the calculated route into more than one route segment and a routecomplexity determining unit 556.

Still referring to FIG. 5, the navigation 500 further includes an inputdevice 513 for executing a menu selection operation, an enlarge/reduceoperation, a destination input operation, etc. and an input deviceinterface 512. In one embodiment, the input device 513 can be the keypad390 in the smartphone device 300. The navigation system 500 alsoincludes a bus 411 for interfacing the above units in the system, aprocessor (CPU) 514 for controlling an overall operation of thenavigation system 500, a ROM 519 for storing various control programssuch as a route search program and a map matching program necessary fornavigation control, a RAM 520 for storing a processing result such as aguide route, a display controller 515 for generating map image (a mapguide image and an arrow guide image) on the basis of the mapinformation, a VRAM 516 for storing images generated by the displaycontroller 515, a menu/list generating unit 518 for generating menuimage/various list images, a synthesizing unit 517, a wirelesscommunication device 509 to retrieve data from a remote server, theInternet or other communication networks, and a buffer memory 510 fortemporary storing data for ease of data processing.

In one embodiment, the CPU 514 may be integrated in the control unit380. Also, the memory device 320 may include the ROM 519 and RAM 520 inthe navigation system 500. The wireless communication device 509 may beoperated with the wireless protocol 330 in the smartphone device 300.

A program for efficiently using a battery in a smartphone with anavigation system in the present invention shown in the flow charts ofFIG. 6 is stored in the ROM 519 or other memory and is executed by theCPU 514. The CPU 514 controls an overall operation of the guidancedisplay method and apparatus in the present invention.

According to another aspect of the present invention, a method for moreefficiently using a battery in a smartphone while operating a navigationsystem therein may include the steps of generating a route based on anaddress or a location entered by a driver 610; dividing the route intomore than one route segments 620; determining route complexity in eachroute segment 630; determining geographical nature of the address orlocation entered by the driver 640; and automatically switching onelocation sensor to another location sensor with different locationaccuracy in the navigation system to maximize the usage of thesmartphone battery 650.

In one embodiment, as mentioned above, when the driver is travellingfrom a complex route segment to a less complex route segment, thelocation sensor is switched to another location sensor with lowerlocation accuracy which consumes less battery power. In anotherembodiment, when the driver is travelling from a less complex routesegment to a complex route segment, the navigation system 500 continuesto use a location sensor with lower accuracy until the navigation system500 determines that switching to higher accuracy location sensor isnecessary to conserve more battery power.

In a further embodiment, the step of automatically switching onelocation sensor to another location sensor when the route complexitychanges 650 includes the step of determining a best timing to switch thelocation sensor with lower location accuracy to another location sensorwith higher location accuracy. In still a further embodiment, the stepof determining a best timing to switch the location sensor with lowerlocation accuracy to another location sensor with higher locationaccuracy includes the step of receiving information including priorcompletion time to the destination and any anticipatory delay;historical and predictive traffic conditions; distance between thecurrent position and destination; and population density of the currentvehicle position, destination and all areas in between.

In an exemplary embodiment, the method for more efficiently using abattery in a smartphone while operating a navigation system therein mayfurther include the step of determining the driver's familiarity of theroute or the geographical nature of the address or location 660. In adifferent embodiment, the step determining the driver's familiarity ofthe route or the geographical nature 660 may include the step ofchecking the driver's historical activities stored in the memory device310.

Having described the invention by the description and illustrationsabove, it should be understood that these are exemplary of the inventionand are not to be considered as limiting. Accordingly, the invention isnot to be considered as limited by the foregoing description, butincludes any equivalents.

1. A method for efficiently using a battery in a smartphone whileoperating a navigation system therein, comprises the steps of:generating a route based on an address or a location entered by adriver; dividing the route into more than one route segment; determiningroute complexity in each route segment; determining geographical natureof the address or location entered by the driver; and automaticallyswitching a current location sensor to another location sensor in thenavigation system when the route complexity or geographical naturechanges, to maximize the usage of the battery in the smartphone.
 2. Themethod of claim 1, wherein when the driver is travelling from a complexroute segment to a less complex route segment, a current location sensoris switched to another location sensor with lower location accuracywhich consumes less battery power.
 3. The method of claim 1, whereinwhen the driver is travelling from a less complex route segment to acomplex route segment, the navigation system continues to use a locationsensor with lower accuracy until the navigation system determines thatswitching to higher accuracy location sensor is necessary to conservemore battery power.
 4. The method of claim 3, wherein the step ofautomatically switching one location sensor to another location sensorwhen the route complexity changes includes the step of determining abest timing to switch the location sensor with lower location accuracyto another location sensor with higher location accuracy.
 5. The methodof claim 1, further comprising the step of determining the driver'sfamiliarity of the route or the geographical nature of the address orlocation.
 6. The method of claim 5, wherein the step determining thedriver's familiarity of the route or the geographical nature includesthe step of checking the driver's historical activities stored in amemory device.
 7. The method of claim 4, wherein the step of determininga best timing to switch the location sensor with lower location accuracyto another location sensor with higher location accuracy includes thestep of receiving information including prior completion time to thedestination and any anticipatory delay; historical and predictivetraffic conditions; distance between the current position anddestination; and population density of the current vehicle position,destination and all areas in between.
 8. A method for efficiently usinga battery in a smartphone while operating a navigation system thereincomprising managing different location sensors in the navigation systemcomprising: means for generating a route based on an address or alocation entered by a driver; means for dividing the route into morethan one route segment; means for determining route complexity in eachroute segment; means for determining geographical nature of the addressor location entered by the driver; and means for automatically switchinga current location sensor to another location sensor in the navigationsystem when the route complexity or geographical nature changes, tomaximize the usage of the battery in the smartphone.
 9. The method ofclaim 8, wherein when the driver is travelling from a complex routesegment to a less complex route segment, a current location sensor isswitched to another location sensor with lower location accuracy whichconsumes less battery power.
 10. The method of claim 8, wherein when thedriver is travelling'from a less complex route segment to a complexroute segment, the navigation system continues to use a location sensorwith lower accuracy until the navigation system determines thatswitching to higher accuracy location sensor is necessary to conservemore battery power.
 11. The method of claim 10, wherein the means forautomatically switching one location sensor to another location sensorwhen the route complexity changes includes means for determining a besttiming to switch the location sensor with lower location accuracy toanother location sensor with higher location accuracy.
 12. The method ofclaim 8, further comprising means for of determining the driver'sfamiliarity of the route or the geographical nature of the address orlocation.
 13. The method of claim 12, wherein the means for determiningthe driver's familiarity of the route or the geographical natureincludes means for checking the driver's historical activities stored ina memory device.
 14. The method of claim 11, wherein the means fordetermining a best timing to switch the location sensor with lowerlocation accuracy to another location sensor with higher locationaccuracy includes means for of receiving information including priorcompletion time to the destination and any anticipatory delay;historical and predictive traffic conditions; distance between thecurrent position and destination; and population density of the currentvehicle position, destination and all areas in between.
 15. A smartphonecomprising: a memory device; a control unit; and a navigation systemcomprising: location sensors with different location accuracies; a routegenerating unit to generate a route based on an address or a locationentered by a driver; a route dividing unit to divide said route intodifferent route segments; a route complexity determining unit todetermine complexity of each route segment; wherein the control unit isconfigured to switch a current location sensor to another locationsensor in the navigation system when the route complexity orgeographical nature changes, to maximize the usage of the battery in thesmartphone.
 16. The smartphone of claim 15, wherein when the driver istravelling from a complex route segment to a less complex route segment,a current location sensor is switched to another location sensor withlower location accuracy which consumes less battery power.
 17. Thesmartphone of claim 15, wherein when the driver is travelling from aless complex route segment to a complex route segment, the navigationsystem continues to use a location sensor with lower accuracy until thenavigation system determines that switching to higher accuracy locationsensor is necessary to conserve more battery power.
 18. The smartphoneof claim 17, wherein the control unit includes means for determining abest timing to switch the location sensor with lower location accuracyto another location sensor with higher location accuracy.
 19. Thesmartphone of claim 15, wherein the control unit further comprises meansfor of determining the driver's familiarity of the route or thegeographical nature of the address or location.
 20. The method of claim19, wherein the means for determining the driver's familiarity of theroute or the geographical nature includes means for checking thedriver's historical activities stored in said memory device.